What is GNU and GPL?
GNU (GNU’s Not Unix) is an on-going project by the Free Software Foundation (FSF) for the purpose of creating a complete, high performance and freely distributable Unix-like computing environment. It was begun by Richard Stallman, a leading advocate of free software, in the latter part of 1983. Most open source software is released under the GPL. This license was carefully designed by Stallman and the FSF to provide the maximum amount of freedom for users of software (including the freedom to copy, study, modify, give away and even sell it) and to prevent software that is initially free from being taken over by any private company that might restrict this freedom.